Esi is a basic analysis and evaluation tool introduced by ISI in 200 1 to measure the performance of scientific research and track the development trend of science. After years of development, this tool, which was originally used to measure and track the development of various disciplines, has become one of the important indicators used to evaluate the academic level of universities around the world.

In recent years, domestic education authorities and universities at all levels have paid more and more attention to ESI indicators. Schools that can enter the top 1% of ESI in the world may be the most likely to be selected as "double-class".

"Double first-class" is a new round of strategic direction for the construction of China University after the "2 1 1" project and the "985" project. All universities go all out to strive for first-class universities and first-class disciplines. ESI is an extremely important reference for how to evaluate first-class universities and first-class disciplines. ESI general statistics are calculated in units of ten years and updated every two months. Aiming at 22 professional fields, this paper comprehensively measures the scientific research level, academic reputation of institutions, academic influence of scientists and academic level of journals from all angles through six indicators, including the number of papers, frequency of cited papers, frequency of all cited papers, highly cited papers, hot papers and cutting-edge papers. The collection covers tens of thousands or even hundreds of thousands of disciplines in different research units around the world.